Abstract

At present, shale gas pressure fracturing volume development technology tends to be mature, shale gas backlog fracturing ends and enters the trial production stage. Due to the improper control of oil nozzle or its causes, the output drops sharply, or the drainage in the production process makes the funnel effect near the wellbore zone, resulting in the closure of the main fracture passage near the wellbore. However, the far-end complex sealing network structure produced by volume fracturing technology is still not fully closed, or secondary fractures occur in the absence of support for the original wellbore fractures or new complex fractures occur in the vicinity of the wellbore. The simple use of high-energy gas fracturing requires low cost, safety and simple and efficient characteristics, and the requirements for surface equipment are not too high. Existing methods mainly include well testing, sand washing by coiled tubing, gas lifting by coiled tubing, wellbore plugging removal, pumping and drainage by supplementary pressure well operator, etc. They can not fundamentally solve the need of closing or reopening new fractures in wellbore, and can not make new complex unclosed fractures near wellbore zone (without secondary fracturing). If the investment of surface equipment for secondary fracturing is similar to that of the first volume fracturing, and the investment is similar, the more complex situation will arise because of filtration and other reasons. At present, low concentration methane in air and wellbore is used to oxidize and exothermic to produce CO2 and H2O, and release energy at the same time. Temperature and pressure are the main means of energy in limited space. High energy gas formed after volume work can help to reopen the original fracture and form a new type of high energy gas fracturing method by means of air ignition and explosion, because the effect of high energy gas fracturing is not affected by stress, new cracks can be produced, and this crack can avoid overlapping with previous cracks. In particular, it can be pointed out that due to the improvement of thermal recovery of heavy oil and other means, the ground operation equipment has the commonality, and reasonable optimization of the construction plan can achieve the established purpose.

摘要

目前，页岩气压力压裂量开发技术趋于成熟，页岩气积压压裂结束进入试生产阶段。由于油嘴控制不当或其原因，产量急剧下降，或生产过程中的排水使井筒附近的漏斗效应，导致井筒附近的主裂缝通道关闭。然而，体积压裂技术产生的远端复杂封闭网络结构仍未完全闭合，或在原有井眼裂缝没有支撑的情况下出现次生裂缝，或在井眼附近出现新的复杂裂缝。高能瓦斯压裂的简单使用要求具有成本低、安全和简单高效的特点，并且对地面设备的要求不是太高。现有的方法主要有试井、连续油管洗砂、连续油管提气、井筒解堵、补压井作业人员抽排等，不能从根本上解决井筒新裂缝的关闭或重新开裂的需要。并且不能在井眼带附近新建复杂的未闭合裂缝（不进行二次压裂）。如果二次压裂地面设备的投资与一次体积压裂相近，投资也相近，则由于过滤等原因，会出现更复杂的情况。目前利用空气和井筒中的低浓度甲烷氧化放热产生CO2和H2O，同时释放能量。温度和压力是有限空间内的主要能量手段。体积功后形成的高能气体有助于重新打开原始裂缝，形成一种利用空气点火爆炸的新型高能气体压裂方法，因为高能气体压裂的效果不受应力影响，新的裂缝可以产生，并且这个裂缝可以避免与之前的裂缝重叠。尤其需要指出的是，由于稠油热采等手段的改进，地面作业设备具有通用性，合理优化施工方案才能达到既定目的。体积功后形成的高能气体有助于重新打开原始裂缝，形成一种利用空气点火爆炸的新型高能气体压裂方法，因为高能气体压裂的效果不受应力影响，新的裂缝可以产生，并且该裂缝可以避免与先前的裂缝重叠。尤其需要指出的是，由于稠油热采等手段的改进，地面作业设备具有通用性，合理优化施工方案才能达到既定目的。体积功后形成的高能气体有助于重新打开原始裂缝，形成一种利用空气点火爆炸的新型高能气体压裂方法，因为高能气体压裂的效果不受应力影响，新的裂缝可以产生，并且这个裂缝可以避免与之前的裂缝重叠。特别需要指出的是，由于稠油热采等手段的改进，地面作业设备具有通用性，合理优化施工方案才能达到既定目的。